cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A262098 Primes p such that 2^p + 9 is also prime.

Original entry on oeis.org

2, 3, 5, 7, 23, 37, 47, 263, 317, 3229, 3253
Offset: 1

Views

Author

Vincenzo Librandi, Sep 18 2015

Keywords

Comments

a(12) > 100000. - Dana Jacobsen, Oct 03 2015
a(12) > 382198 using A057196. - Michael S. Branicky, Oct 31 2024

Examples

			5 is in sequence because 2^5 + 9 = 41 is prime.
		

Crossrefs

Subsequence of primes of A057196.
Cf. primes p such that 2^p+k is a prime: A057736 (k=3), A175173 (k=5), this sequence (k=9), A155780 (k=11), A175234 (k=15), A262099 (k=17), A175235 (k=21), A175236 (k=23), A262934 (k=27), A262100 (k=29), A262201 (k=33), A262962 (k=35).

Programs

  • Magma
    [p: p in PrimesUpTo(1000) | IsPrime(2^p+9)];
    
  • Mathematica
    Select[Prime[Range[1000]], PrimeQ[2^# + 9] &]
  • PARI
    for(n=1, 1e3, if(isprime((2^prime(n))+9), print1(prime(n)", "))) \\ Altug Alkan, Sep 18 2015
    
  • Perl
    use ntheory ":all"; use Math::GMP qw/:constant/; forprimes { say if is_prime(2**$+9) } 10000; # _Dana Jacobsen, Oct 03 2015
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